Group 6 - Black & Decker Drill

Contents

Introduction

Black and Decker DR202 Drill

Our group was given the task of analyzing, dissecting and reanalyzing a Black & Decker DR202 Power Drill. Through this process we will gain knowledge of design factors and understand how and why decisions were made in the development process. We will present our project in five different gates that each focus on a different aspect of the project.

Executive Summary

A power drill is a must have tool for common household repairs. The Black & Decker DR202 Power Drill is designed with functionality and efficiency in mind to make repairs effortless. It has the ability to both remove and insert screws with ease. The uniquely molded handle is ergonomically designed to make the user interface more pleasing and on-drill bit storage adds convenience to the user. The implication of gear reduction generates sufficient torque to decrease the amount of energy the user must input. The DR202 is designed to be plugged into a common wall outlet so there does not need to be a change in voltage between the outlet and the drill. A keyless chuck also makes jobs faster for the user and eliminates the hassle of extra pieces that can potentially be lost. Aesthetically, the drill is made of plastic and rubber in the typical Black & Decker colors.

As we started to analyze drill, we came to an understanding of how the original manufacturer had to take into consideration outside factors and constraints that went into designing the drill. The four factors; global, economic, societal, and environmental factors contribute to the initial design of the drill. The manufacturer of the drill has to take into account the global market in order to sell the drill efficiently. Each country has different shaped outlets and a different standard house voltage that change the way the drill has to be made. For each different location, the manufacturer must change the plug and voltage in the drill to fit the parameters of the country that it is being sold in. This can drastically change the way the drill is made for each location, unless a universal cord holder in the drill is used to eliminate changing the drill housing due to a different wire size. The manufacturer must also change the language of the faceplate based on different locations of use, but keep a universal size for the faceplate to eliminate major changes in the drill housing. Societal factors that the manufacturer had to take into consideration were the ease of use of the drill and the safety the drill provides to the user. The DR202 Drill features a keyless chuck, which makes changing bits easier and quicker for the user. It also features a level which helps in projects that require the screws to be square with the surface. Safety is another large societal concern for manufacturers. Moving parts in the drill must be properly enclosed to prevent user injury during usage. The shape and size of the casing and ventilation holes in the casing are directly affected by this factor. The housing of the drill encloses the moving motor well and it provides sufficient ventilation for the excess heat from the movement of the motor. As with any other product, there are also considerations with economics for the production of the drill. The manufacturer chose certain materials and production processes that limited the amount of money spent on the product while maximizing the lifespan and quality of the product. They chose cheep plastics and metals to make up the components that also were stronger than average. The last factor that the manufacturer had to consider was the environmental impact the drill will have. This takes into account any type of pollution that the drill outputs, especially the materials it is made out of. The manufacturer chose to use materials that can mostly be recycled or reused on a different product so as to keep pollution from the drill to a minimum.

We then dissected the drill. This dissection process allowed us to understand the sub-systems of the drill and, ultimately, the components that made up the drill. By studying the components closely, we understood how they were made and what could be done to improve the drill by changing these components and the sub-systems they belong to. An example of a proposed revision that we stated was changing the drill from a corded drill to a battery powered drill. This would allow for the drill to be more mobile while adding another feature to the drill. This design revision, though simple, had to be considered with the four factors before it could be a major design revision. The global factor of this revision is that the drill can now be sold anywhere in the world without changing the battery, where the plug would have to change if it was corded. The disadvantage of the battery is that the charger for it would have to be changed depending on where the drill is being sold. Societal concerns with this revision was the ease of use of the drill. With this revision, the drill would have greater mobility at the cost of weight. The weight of the drill would increase slightly, due to the battery. Thought this is a disadvantage, most people would buy a cordless drill instead of a corded drill because of the limited area they can operate in. The economics that influence this revision are ones dealing with manufacturing the battery and changing the mold for the drill housing. Because the battery is larger than a cord, the drill housing mold would have to change based on the size of the battery. This would initially cost the company money, but the quality of the drill would increase and there would be an increase in sales, offsetting this cost. Environmentally, since the battery is a rechargeable battery, there would be little pollution due to the change. Though the battery is acidic and harmful to the environment, the batteries would have to be disposed of properly, but not many batteries would be disposed of because of their life expectancy.

During the dissection process, we also gained a knowledge of production processes and energy conversions inside the drill. This allowed us to understand how electric motors and drills change electric energy into rotational mechanical energy. In our drill, the stator, a hollow cylinder shaped component inside the drill, imports electrical energy from the power cord to convert that energy into a magnetic field. The stator is shaped like a solenoid and the properties of it help to make a uniform magnetic field inside the stator. The armature rests inside the stator and the magnetic field from the stator induces a current in the armature. This sets up a magnetic field that is opposite to that of the stator and rotates the armature. The armature is connected to a gear system that then outputs the rotational energy to the bit.